Giving traffic the green light

Nick Bergseng and Ricky FranchiPhoto: Heidi Williams

Nick Bergseng and Riccardo Franchi, senior computer science and engineering students, don’t just view waiting at stoplights as a frustrating inconvenience, the way most of us do. Instead, when they see cars inch from one red light to the next, they recognize the millions of hours of productivity being lost and the tons of CO2 needlessly emitted into the atmosphere. So they focused their attention on this problem for their senior design project.

“Obviously, if you hit one green light while driving the speed limit, you should hit the next and the next,” they said. “Although most stoplights have their own traffic controller that takes in information from a corresponding inductive metal plate installed in the road, the controllers don’t communicate from one light to the next along the street. This seemed like a simple fix to us,” they continued. “It’s the talking back and forth that is missing.”

“Large cities around the country are addressing this problem with elaborate, high-tech traffic control systems that are impressive, but are outside the scope of what is essential to keeping traffic moving and minimizing wait time,” said Bergseng, “And with a $20 million price tag, they are out of reach for smaller, budget-constrained cities like Santa Clara. It would be like having a flat tire on your bicycle and buying a Ferrari instead of just patching the tire up.” Franchi added, “We knew we could ‘McGuyver up’ a low-cost system that would work.”

Their proof of concept solution uses Quadstone Paramics software and an inexpensive, commercially-available microcontroller to connect existing signal controllers via the Internet. It may not be high tech, but it is appropriate technology for the task—an important consideration for local governments managing limited funds. “Ta-dah!,” they said, “New light timings at a cost that is four orders of magnitude cheaper! At a minimum cost, we’ve come up with a system that is appropriately scaled, modular, ready to implement, and easily upgraded.”

Bergseng and Franchi say that working on this year-long project has been a great experience. “This is what we’re going to be spending the next 30 years or so doing—taking a problem, finding a solution, presenting a design and implementing it,” said Franchi. Bergseng agreed, “I love the senior design project. People say you learn more in a week on the job than you do in all your classes; this gives you the opportunity of having that ‘week on the job’ type of experience you don’t get in class or lab.”